Liquid crystal display devices include pixels corresponding to for example R (red), G (green), and B (blue), respectively. In a liquid crystal display device of a monogap structure which has a uniform liquid crystal layer thickness, coloring occurs at an oblique viewing angle particularly in black display (for example, bluish black), caused by wavelength dependence in retardation of a liquid crystal layer. So that this coloring is reduced in degree, brightness characteristics (gamma curve) against gray scale are set per R, G, and B pixels, however this causes a decrease in contrast due to a change in the brightness of black from a front view perspective. In view of this, a multigap structure has been suggested as a method which allows for reducing such a coloring while maintaining its contrast: the multigap structure changes a thickness of the liquid crystal layer per R, G, and B pixels, to compensate the wavelength dependence in retardation (for example, see Patent Literature 1).
It is known that in the liquid crystal display device, a parasitic capacitor Cgd is formed between the drain electrode of the transistor (and pixel electrode electrically connected to the drain electrode) and the scanning signal line, and a parasitic capacitor Csd is formed between the drain electrode of the transistor (and pixel electrode electrically connected to the drain electrode) and a source electrode of the transistor (and the data signal line electrically connected to the source electrode), as illustrated in FIG. 16. Caused by these parasitic capacitors, electric potential of the pixels (pixel electrodes) decrease when the transistor turns OFF (when the scanning signal is deactivated). This amount (absolute value) of decrease in the electric potential is called a feed-through voltage (ΔQ), and S−ΔQ denotes an effective electric potential on the pixel where S is a signal potential applied on a pixel (hereinafter, an absolute value of the effective potential in accordance with electric potential Vcom of a common electrode is referred to as “effective voltage”). Note that the feed-through voltage ΔQ=Cgd×(VH−VL)/(Ccs+Csd+Cgd+Clc), where VH is an active electric potential of a scanning signal supplied to a scanning signal line, VL is an inactive electric potential, Clc is a liquid crystal capacitor, and Ccs is a storage (auxiliary) capacitor.
Hence, as illustrated in FIG. 21, while gray scale X is continuously displayed on the R pixel, the R pixel alternately receives a signal potential SHRX (at positive drive) and a signal potential SLRX (at negative drive), which sets the signal potential SHRX as an effective potential EHRX at the positive drive+ΔQx and sets the signal potential SLRX as an effective potential ELRX at the negative drive+ΔQx. Note that since a middle value of the effective potential EHRX at the positive drive and the effective potential ELRX at the negative drive is (EHRX+ELRX)/2={(SLRX+SHRX)/2}−ΔQx=Vcom (electric potential of the common electrode), a middle value SMRX of the signal potential SHRX and the signal potential SLRX is (SHRX+SLRX)/2, which is Vcom+ΔQx.
Moreover, as illustrated in FIG. 21, while the gray scale X is continuously displayed on the G pixel, the G pixel alternately receives a signal potential SHGX (at positive drive) and a signal potential SLGX (at negative drive), which sets the signal potential SHGX as an effective potential EHGX at the positive drive+ΔQx and sets the signal potential SLGX as an effective potential ELGX at the negative drive+ΔQx. Note that since a middle value of the effective potential EHGX at the positive drive and the effective potential ELGX at the negative drive is (EHGX+ELGX)/2={(SLGX+SHGX)/2}−ΔQx=Vcom (electric potential of the common electrode), a middle value SMGX of the signal potential SHGX and the signal potential SLGX is (SHGX+SLGX)/2, which is Vcom+ΔQx.
Moreover, as illustrated in FIG. 21, while the gray scale X is continuously displayed on the B pixel, the B pixel alternately receives a signal potential SHBX (at positive drive) and a signal potential SLBX (at negative drive), which sets the signal potential SHBX as an effective potential EHBX at positive drive+ΔQx and sets the signal potential SLBX as an effective potential ELBX at negative drive+ΔQx. Note that since a middle value of the effective potential EHBX at the positive drive and the effective potential ELBX at the negative drive is (EHBX+ELBX)/2={(SLBX+SHBX)/2}−ΔQx=Vcom (electric potential of the common electrode), a middle value SMBX of the signal potential SHBX and the signal potential SLBX is (SHBX+SLBX)/2, which is Vcom+ΔQx.
As such, while identical gray scales X are displayed on each of the R pixel, G pixel, and B pixel, the middle value SMRX of the signal potentials applied on the R pixel, the middle value SMGX of the signal potentials applied on the G pixel, and the middle value SMBX of the signal potentials applied on the B pixel coincide.